This is one of Leonardo's least-known designs and he probably developed it during his extensive studies and dissections of the human body. The robot is thought to have been designed just prior to the period of the Last Supper; this would put it at around 1495. It was probably the first ever design for a humanoid robot, and if built, was most certainly the first ever manufactured. The finished robot drawings are among the some 14,000 pages of Leonardo's work which remain lost to us, and experts have no indication that this machine progressed beyond Leonardo's initial sketches.

It wasn't actually until the 1950s that a professor from the University of California suggested some of Leonardo's designs could be for a robot. A further forty years passed before the components of a system for automatically controlling limb movements was identified among the sketches.

This led the Florence-based Institute and Museum of the History of Science to develop computer models designed to establish the feasibility of Leonardo's sketches. These simulations clearly confirmed that the drawings were for a mechanical robot.

It is now obvious that Leonardo designed his robot to open and close its jaw (which was anatomically correct) sit up, wave its arms, and move its head. Though uncertainty exists about sound it may used automated drums. The mechanical man was dressed in a suit of armor from the late fifteenth century.

We still do not know what device Leonardo planned to use to activate his robot, but it was most likely water or weights.